Description of Olea capensis L. Subsp. enervis (Harv. ex C.H.Wright) I.Verd.
Olea capensis L. Subsp. enervis (Harv. ex C.H.Wright) I.Verd. commonly known as the forest olive, is a forest tree species native to Southern Africa. It belongs to the Oleaceae family and is closely related to the domestic olive tree.
Origin and Distribution
Olea capensis L. Subsp. enervis is mainly found in South Africa, Swaziland, and Zimbabwe. The species is commonly found in open forests, bushlands, and grasslands. It is a hardy species that can grow in rocky soils and can survive in areas with low rainfall.
Common Names
The species has several vernacular names, including iNcera (Zulu), Muhuhu (Shona), Umdwenkla (Swati), umNquma (Xhosa), and Muvhuyu (Venda).
Uses
The forest olive tree is a valuable source of timber. Its wood is hard, heavy, and durable, making it ideal for construction and furniture-making. The species also has several medicinal properties. In traditional medicine, the bark of the tree is used for treating fevers, colds, and diseases of the respiratory system. The leaves are used to treat wounds, and the bark extract is used as a tonic.
General Appearance
The forest olive tree can grow up to 20 meters in height and has an irregular crown. The trunk of the tree is usually short and has a diameter of up to 1 meter. The bark is gray and smooth when young but becomes rough and scaly with age. The leaves are dark green, glossy, and lance-shaped, with a pointed tip. The flowers are small and greenish-white, and the fruits are small and purple when ripe and contain a single seed.
Light Requirements
Olea capensis L. subsp. enervis thrives in full sun exposure. Therefore, this plant requires at least 6 hours of sunlight per day. However, they can also tolerate partial shade, but their growth rate and foliage quality may be affected.
Temperature Requirements
This plant is native to South Africa and can tolerate a wide range of temperatures. The preferred temperature range for Olea capensis L. subsp. enervis is 12 – 35°C. They can withstand hot and dry conditions, but they should be protected from frost and extreme cold.
Soil Requirements
Olea capensis L. subsp. enervis prefers well-draining soil with a pH range of 6.0 – 7.5. They can tolerate a range of soil types but perform best in organic-rich sandy loam soil. The plant requires moderate watering levels, and excessive watering should be avoided as it can cause root rot.
Cultivation methods:
Olea capensis L. subsp. enervis grows well in well-drained soils that are rich in organic matter. It prefers full sun exposure and can tolerate partial shade. The plant can be propagated by seeds or cuttings.
Watering needs:
Olea capensis L. subsp. enervis prefers regular watering during the growing season to keep the soil consistently moist but not waterlogged. The frequency of watering may vary depending on the local weather conditions and the soil type. The plant can tolerate mild drought conditions, but it is essential to avoid prolonged dry periods as it can impact the growth and productivity of the plant.
Fertilization:
It is recommended to fertilize Olea capensis L. subsp. enervis during the growing season to stimulate growth and productivity. A balanced fertilizer with a higher proportion of nitrogen and potassium is suitable for this plant. The application of fertilizer may vary depending on the soil conditions, but a standard recommendation is to fertilize once every two months during the growing season.
Pruning:
Pruning is an essential aspect of maintaining Olea capensis L. subsp. enervis. It is recommended to prune the plant during the dormant season to remove dead, diseased, or damaged branches. It can also help to shape the plant and promote new growth. The pruning technique may vary depending on the growth habit and preference of the gardener, but it is crucial to avoid aggressive pruning as it can impact the plant's health.
Propagation Methods for Olea capensis L. subsp. enervis (Harv. ex C.H.Wright) I.Verd.
Propagation of Olea capensis L. subsp. enervis can be done through both sexual and vegetative methods. The choice of propagation method should depend on the desired outcome, as well as the resources available.
Sexual Propagation
Sexual propagation of Olea capensis L. subsp. enervis involves the planting of seeds. The best time to plant the seeds is in the fall, just before the rainy season. The seeds should be planted at a depth of about 1 inch and spaced evenly apart. The soil should be kept moist until germination, which should occur within 3 to 8 weeks. The resulting seedlings can be transplanted into individual pots or directly into the ground after they reach a height of about 4 inches.
Vegetative Propagation
Vegetative propagation of Olea capensis L. subsp. enervis can be done through cuttings or layering.
Cuttings: Take cuttings from semi-hardwood in the late spring or early summer. Remove all leaves except for a few at the tip. Dip the cut end in rooting hormone and place in a well-draining potting mix. Keep the soil moist and in a warm, bright location until the cuttings begin to root. After the roots have formed, the cuttings can be transplanted to individual pots or directly into the ground.
Layering: Pick a stem with healthy growth and bend it towards the ground in late spring or early summer. Make a small cut in the bark where the stem touches the ground and cover it with soil, leaving the tip of the stem exposed. Keep the soil moist and in a warm, bright location until the stem begins to root. Once the stem has rooted, it can be severed from the parent plant and transplanted to its permanent location.
Disease and Pest Management for Olea capensis L. subsp. enervis
Olea capensis L. subsp. enervis is generally a healthy plant that is not affected by many diseases and pests. However, extreme weather conditions and improper care can make it susceptible to various diseases. Here are some common diseases and pests that might affect the plant and ways to manage them:
Diseases
Anthracnose: This is a fungal disease that causes brown spots on the leaves and can also infect the fruit. To manage anthracnose, prune off any infected plant parts and dispose of them. Also, avoid overhead watering and maintain good air circulation around the plants.
Phytophthora root rot: This is a soil-borne fungal disease that causes the roots to rot, leading to stunted growth and eventual death of the plant. To manage phytophthora root rot, ensure the soil is well-drained and avoid over-watering. Also, plant the Olea capensis in areas with good soil drainage.
Verticillium wilt: This is a fungal disease that causes leaves to wilt and fall off. The disease can also cause yellowing of leaves. To manage verticillium wilt, remove affected plant parts and dispose of them. Also, avoid over-watering and apply a fungicide to prevent further spread of the disease.
Pests
Olive fly: This is an insect pest that lays eggs inside the fruit. The larvae then feed on the fruit, causing it to rot. To manage olive fly, use pheromone traps to monitor the population of the pest. You can also apply insecticides to the fruit to kill the larvae.
Olive moth: This is an insect pest that causes damage to the fruit. The larvae of the olive moth feed on the fruit, causing it to rot. To manage the olive moth, prune off any affected plant parts and use pheromone traps to monitor the population of the pest. Also, apply insecticides to the fruit to kill any larvae that may be present.
Olive scale: This is an insect pest that sucks sap from the leaves, causing them to turn yellow and wilt. To manage olive scale, prune off any affected plant parts and use insecticides to kill the pests. Also, maintain good plant hygiene by removing any fallen leaves or fruits that may harbor the pests.
